1. Field of the Invention
The invention relates to a 3/2-port directional-control valve for controlling the injection of fuel in a common rail injection system of an internal combustion engine, with a first switched position in which an injection nozzle is connected to a fuel return and with a second switched position in which the injection nozzle is connected to a high-pressure fuel reservoir.
2. Description of the Prior Art
A 3/2-port directional-control valve of the type with which this invention is concerned is known, for example, from DE 197 24 637 A1. In common rail injection systems, a high-pressure pump supplies the fuel into the central high-pressure reservoir, which is referred to as the common rail. High-pressure lines lead from the rail to the individual injectors, which are associated with the cylinders of the engine. The injectors are individually triggered by the engine electronics. When the control valve opens, highly pressurized fuel travels past the nozzle needle, which has been lifted up counter to the prestressing force of a nozzle spring, and into the combustion chamber.